The present invention is directed to the use of a non-volatile programmable memory storage system for electronic musical instruments utilizing an erasable and reprogrammable read only memory (EPROM). This system is adaptable to any electronic musical instrument control circuit where user reprogrammable read only memory storage or decoding is desirable.
The use of memory devices in electronic musical instruments is known in the prior art. For example a rhythm pattern generator system is known where the memory device is used to activate a sequence of rhythm voices during the pattern generation. However, in a conventional system of this type, there is the limitation that the memory pattern is fixed and cannot be modified except by replacing the memory integrated circuit with another integrated circuit containing a different coding pattern. This is a relatively expensive procedure and is beyond the capability of the typical user of such a system to implement. Random access memories (RAM) on the other hand, although more readily adaptable to reprogramming by the user, are a volatile type of storage element and must be reprogrammed each time the power is turned off in the system. Other types of memory storage systems from the prior art such as paper tape, cards, magnetic tape or optical discs are not readily adaptable to low cost large-scale integrated circuit designs and require much additional peripheral equipment such as card punches and recorders to program. The present invention circumvents the shortcomings and limitations of these prior art systems and presents a novel and practical method of providing user programmable non-volatile storage in electronic musical instruments which is adaptable to low cost, large-scale integrated circuit design.